PATENTS

      134.     ------.  [BARR, F. T.]  (Standard Oil Development Co.).  Hydrocarbon Synthesis.  United States Patent 2,467,802, Apr. 19, 1949: appl. filed Dec. 14, 1945.  Serial No. 635,100: 11 claims (Cl. 260-449.6).  Chem. Abs., vol. 43, 1949. p. 6811.

Gives method for controlling activity of the fluid catalyst used in the Fischer-Tropsch synthesis by using a multistage series operation and charging each stage with catalyst withdrawn from a subsequent stage, in the order of flow of synthesis gas.  For example: fresh synthesis gas may be supplied to the 1^st of a series of fluid catalyst zones and from the 1^st zone to 1 or more subsequent zones.  Fresh catalyst may be charged to a last zone while catalyst of average activity is withdrawn, preferably at the same rate, and charged to the next preceding zone, wherein it is further deactivated in contact with relatively fresh synthesis gas.  The average catalyst activity in this latter zone will be lower than that in the 1^st catalyst zone.  This procedure may be repeated until catalyst of lowest average activity is maintained in and may be withdrawn from the 1^st fluid catalyst zone that receives the fresh synthesis gas.